\\[-1.8ex] Soil Heterogeneity & $-$0.110$^{***}$ & $-$0.112$^{***}$ & $-$0.100$^{***}$ & $-$0.081$^{**}$ & $-$0.059$^{**}$ & $-$0.066$^{***}$ \\ 
  & (0.040) & (0.040) & (0.036) & (0.036) & (0.026) & (0.025) \\ 
\\[-1.8ex] 
Observations & 23,443 & 23,443 & 23,443 & 23,443 & 23,443 & 23,381 \\ 
R$^{2}$ & 0.009 & 0.045 & 0.143 & 0.184 & 0.226 & 0.230 \\ 
